Study: Microbes to protect coasts as oceans acidify

This image shows star-shaped foraminifera from the Great Barrier Reef in Australia. Researchers from the University of Bonn found out that such tiny foraminifera in the oceans can save islands.

Ancient single-celled organisms called foraminifera may protect coastlines from stormy weather in the coming era of warmer and more acidic oceans, according to a new study.

That’s because the microscopic shelled creatures, called forams for short, each produce about .4 pounds of calcium carbonate per square foot of ocean floor. Calcium carbonate is the limestone material that forms the bedrock of coral reefs and comprises about 4 percent of the Earth’s crust.

Coral organisms also produce calcium carbonate, but they are more sensitive to the increasing acidity of the oceans due to the absorption of carbon dioxide from the atmosphere.

"Benthic forams excel where reef building organisms fail," Martin Langer, a researcher at the University of Bonn, told NBC News in an email.

He and colleagues studied the range expansion of the star-shaped foram Amphisteginid foraminifera during ancient bouts of global warming and then used that data to build a model to forecast the microbe’s range as the planet warms.

The researchers found the foram will spread 112 miles closer to the poles by 2050 and nearly 190 miles by 2100, assuming warming of 4.5 degrees Fahrenheit. As it creeps towards the poles, it will continue to build up deposits of calcium carbonate.

These deposits, in turn, will offer the type of coastal protection that coral reefs provide today, according to Langer. If so, is it possible to expedite the spread of forams to build in this coastal resilience?

"Needs to be tested," he said. "Some South Pacific reef islands, where forams are the major producers of (calcium carbonate), are equally resistant to the ongoing climate change as the typical coral reef islands."